Current Topics

The heterogeneity of REM sleep

Rapid Eye Movement sleep is a unique sleep state characterized by intense sensorimotor and oneiric (dream) activity accompanied by inhibited motor output and reduced environmental processing. Nevertheless, REM sleep is composed of two, markedly different brain states, a phasic and a tonic microstate that alternate during REM sleep cycles. These microstates differ regarding arousal thresholds, sensory processing and presumably mental activity. Our aim is to examine the dynamic aspects of sleep-specific neural activity within the phasic and tonic REM state in order to understand their functions, as well as their relevance to information-processing and influence on dream experiences.

Nightmares

Nightmares are intense and highly unpleasant mental experiences that occur usually – but not exclusively – during late-night Rapid Eye Movement (REM) sleep and often provoke abrupt awakenings. The clinical relevance of nightmares should not be underestimated given their high incidence in psychiatric populations, co-morbidity with insomniac symptoms and their association with waking affective as well as cognitive dysfunctions. In this line of research we investigate the personality correlates, neurocognitive and neurophysiological aspects of nightmare disorder. Our aim is to develop an integrative model of nightmare disorder that might facilitate the scientific understanding of this specific sleep disorder and foster therapeutic interventions and treatment procedures.

Chronotype, personality and cognition

This line of research examines diurnal preferences (morningness-eveningness) in relation to psychological adjustment and sleep quality in healthy and psychiatric populations. In addition, we are interested in the effects of synchrony; therefore, we examine how the time of testing modulates the associations between chronotype and cognitive performance.

Sleep and memory consolidation

Off-line memory consolidation is influenced by emotional, reward-related and cognitive processes during encoding. Research indicates that sleep selectively facilitates the consolidation of memories that are relevant for the future. In our laboratory, we are investigating the role of sleep (daytime naps and nocturnal sleep) in off-line memory consolidation. In our experiments, we are manipulating the perceived relevance of newly acquired memory elements to examine the effects of sleep on memory performance. By these experiments, we would like to examine the consolidation processes of relevant and irrelevant memories. Furthermore, we are interested in the association between the consolidation of relevant material, sleep macrostructure and sleep-specific oscillations.